1. Field of the Invention
The present invention is directed to a photodiode array of the type suitable for use in an x-ray detector which converts the energy of incident x-rays into a corresponding electrical signal.
2. Description of the Prior Art
X-ray detectors are employed in medical examinations, such as in x-ray computed tomography, the x-ray detector serving to convert incident x-rays into corresponding electrical signals. The most widely employed x-ray detectors in this context are in the form of an array of xenon ionization chambers, or scintillators followed by photodiodes.
In a scintillator/photodiode array, the scintillator converts incident x-ray quanta into photons. The photodiode, disposed following the scintillator in the radiation propagation direction, absorbs the photons and a photocurrent is thus obtained that is proportional to the luminous intensity of the incident x-ray.
Problems associated with the use of such photodiode arrays in an x-ray detector are that a small portion of the incoming x-ray quanta may penetrate to a slight extent directly into a photodiode in the array, thereby producing an unwanted noise signal, and cross-talk between detector channels must be avoided.